Impact of underground near surface ore body mining on the stability of overburden and dangerous rock masses

In order to explore the impact of near surface ore body mining on the stability of overburden and surface dangerous rock masses, a Phosphate Mine was used as the engineering background. On-site investigation method was adopted to clarify the stability conditions of the surface dangerous rock. Numerical analysis software was used to simulate the evolution laws of overburden deformation, stress, and plastic zone. The research results indicate that the development of interlayer structural planes in the surrounding rock of the roof of the mining area can easily cause the collapse of the roof slab or sheet. The strata are hard and brittle in lithology, with developed rock fractures. Dangerous rock blocks are formed under the combination of fissures and rock layers. The mining disturbance generated during the mining process is relatively small. The impact on the rock layers, adjacent mining sites, and surface stability is weak. The surface is less affected by the mining of underground ore bodies and has not reached the maximum allowable value. Under the condition of first mining the ph1# ore body and then mining the ph2# ore body, the displacement of the overburden is relatively small. There is no distribution of connectivity in the plastic zone in the mining pillars, mining areas, and overburden. The research results can provide theoretical reference for the feasibility analysis of near surface ore body mining in similar mines.